Device for shock-deformation of workpieces

ABSTRACT

An explosive performing device comprises a chamber composed of a plurality of walls. Either the top and bottom wall are movable toward and away from one another between a chamber-closing and a chamber-opening position; alternately the top and bottom wall may be stationary and the circumferential wall could be composed of at least two sections which are so movable. The inertia of the movable walls is so selected that it at least substantially equals the shock pressure necessary for producing the energy level required to obtain the deformation of a workpiece into conformance with the surface contour of one or more dies located in the interior of the pressure chamber. An explosive device serves to produce a sudden increase in pressure in the chamber. Energy-consuming connecting means connects those walls which are movable relative to one another and serves to consume shockpressure energy in excess of the predetermined energy level during the relative movement of the walls from chamber-closing to chamber-opening position.

United States Patent [72] Inventors Heinrich Hertel Tannenbergallee 38; Dietrich Ruppin, Bolchenerstrasse 10, both of Berlin, Germany [21] Appl. No. 860,752

[22] Filed Sept. 24, 1969 [45] Patented Jan. 4, 1972 [73] Assignee said Hertel, by said Ruppin (32] Priority Sept. 25, 1968 I 3 3 Germany I31] Pl777209.7

I54] DEVICE FOR SHOCK-DEFORMATION OF Primary ExaminerRichard .l. Herbst Attorney-Michael S. Stn'ker ABSTRACT: An explosive performing device comprises a chamber composed of a plurality of walls. Either the top and bottom wall are movable toward and away from one another between a chamber-closing and a chamber-opening position; alternately the top and bottom wall may be stationary and the circumferential wall could be composed of at least two sections which are so movable. The inertia of the movable walls is so selected that it at least substantially equals the shock pressure necessary for producing the energy level required to obtain the deformation of a workpiece into conformance with the surface contour of one or more dies located in the interior of the pressure chamber. An explosive device serves to produce a sudden increase in pressure in the chamber. Energy-consuming connecting means connects those walls which are movable relative to one another and serves to consume shock-pressure energy in excess of the predetermined energy level during the relative movement of the walls from chamberclosing to chamber-opening position.

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I INVENTOR. Hemmca Hears-w BY merit-(cu 120 PP add! (-I/ 'L BACKGROUND OF THE INVENTION The present invention relates to a device for shock-deformation of workpieces in general, and more particularly to such a device which has a self-venting pressure chamber.

The deformation or forming of workpieces by shock, that is by setting off explosives or analogous means, is already known. It is also known to utilize self-venting pressure chambers in such devices, that is pressure chambers wherein one or more walls move to a position in which the pressure chamber is opened when the pressure in the chamber reaches and exceeds a predetermined level. Usually, the means for maintaining the movable wall or walls in closed position against the developing pressure-until the pressure reaches the predetermined levelrequire quite significant structural and technological expenditures because of the forces which must be restrained. An attempt to simplify such devices is described in German Pat. No. l 259 825 which teaches a device wherein the pressure chamber is bounded by stationary and movable walls, with the mass of the movable walls being so selected that the developing pressure in the interior of the pressure chamber is largely counteracted-until it reaches the predetermined level at which venting is desired-by the inertia of the masses. This is a significant improvement over the constructions known prior to this teaching. However, because in the device according to German Pat. No. l 259 825 one of the masses to be accelerated moves vertically upwardly and the other vertically downwardly, reaction forces are inevitably transmitted to the supporting frame of the device because only the upwardly moving mass is free to perform its movement, whereas the downwardly moving mass is limited in its freedom of movement, for instance by means of springs.

Evidently, if it would be possible to avoid the transmission of reaction forces to the support structure, it would be possible to make the device less complicated and therefore more economical in its construction, and to obtain other advantages which will be set forth herein subsequently.

SUMMARY OF THE INVENTION It is, accordingly, an object of the present invention to provide an improved device for shock-deformation of workpieces.

An additional object and a more specific one is to provide such a device which is simpler and less expensive in its construction than was heretofore possible.

A further object of the invention is to provide such a device which is smaller than heretofore possible.

In pursuance of the above objects, and others which will become apparent hereafter, one feature of the invention resides, briefly stated, in a device for shock-deformation of workpieces which comprises wall means surrounding a pressure chamber arranged to accommodate a workpiece and a die having a surface contour which is to be imparted to the workpiece for shock-deformation of the latter into conformance with the surface contour. According to the invention, the wall means includes at least two walls at least one of which is movable relative to the other between a chamberclosing position and a chamber-opening position, and the wall means has an inertia so selected as to at least substantially equal the necessary shock-pressure for producing the predetermined energy level requisite to obtain the desired deformation of the workpiece so that upon exceeding of the necessary shock-pressure relative movement of the walls to the chamber-opening position results with concomitant venting of the chamber. Shock-pressure producing means is provided for producing a sudden increase in pressure in the chamber. Energy-consuming connecting means connects the walls to one another and is operative for consuming shockpressure energy in excess of the predetermined level during relative movement of the walls to chamber-opening position.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical section through an apparatus according to the present invention;

FIG. 2 is a top plan view of FIG. 1 with the outer casing of the apparatus omitted for the sake of clarity;

FIG. 3 is a view similar to FIG. 1 but of a further embodiment of the invention;

FIG. 4 is a section taken on the line IVIV of FIG. 3 but with the outer casing of FIG. 3 omitted;

FIG. 5 is a view similar to FIG. 3 showing a further embodiment of the invention;

FIG. 6 is a section taken on the line VI-Vl of FIG. 5;

FIG. 7 is a section taken on the line VII-VII of FIG. 5; and

FIG. 8 is a view similar to FIG. 5 but illustrating yet an additional embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing firstly the embodiments illustrated in FIGS. 1 and 2, it will be seen that reference numeral 1 identifies the top wall, and that reference numeral 2 the bottom wall of a pressure chamber which is defined, in conjunction with the walls 1 and 2, by a circumferential wall composed of a plurality of sections 4. The top and bottom walls, 1 and 2, are connected immovably with one another by means of the bolts 3. According to the present invention, the sections 4 of the circumferential wall, however, are connected with one another for relative movement. It is emphasized that while four of the sections 4 have been illustrated in FIG. 2, the number may be greater or smaller, except that at least two sections must be provided in order to obtain the construction according to the present invention.

The sections 4 in the illustrated embodiment of FIGS. 1 and 2 have abutting flanges 4a provided with suitable bores through which the bolts 12 extend. Interposed between the heads of the bolts 12 and the respective flange 4a, are elastically yieldable elements 13, such as springs which in the illustrated embodiment are illustrated as elements of elastomeric material. Thus, movement of two abutting flanges 4a away from one another, in a sense opening a gap 14 between them, results in compression of the respective elements 13, and, after the chamber has been vented, in restoring of the flanges 4a into abutting position by the expanding elements 13.

In the illustrated embodiment, a shock-producing means is mounted in the top wall I and may be in form of an explosive cartridge 5 and actuating means 6 therefor. Neither the cartridge 5 nor the actuating means 6 requires detailed discussion herein because they are well known in the art and do not in themselves form a part of the present invention. Needless to say, other means for producing a sudden increase in the pressure in the interior of the pressure chamber is also conceivable and could be employed with the present invention without detracting from the inventive concept.

Mounted on the inwardly facing side of the bottom wall 2 is a die 7 having a predetermined surface contour here shown to be recessed, and overlying this recessed surface contour is a workpiece 8, which is to be deformed into conformance with the surface contour. Sealing means 9 seals the workpiece 8 with reference to the surface of the die 7, so that the two define between themselves a hollow space 10 which in known manner is evacuated through the evacuating conduit 11. It is emphasized that evidently the surface contour to which the workpiece 8 is to be deformed can also be provided directly in the bottom wall 2, rather than in a separate die 7 as illustrated.

The construction and configuration of the resilient elements 13 is such, as is the construction of the sections 4, that it is the inertia of the masses of the sections 4 which resists the increasing pressure in the interior of the chamber upon actuation of the shockrpressure producing means, until such time as the predetermined peak pressure has been reached. Thereupon, the abutting flanges 4a of adjacent ones of these sections 4 move apart, opening the gaps 14, and the pressure is vented from the interior of the chamber.

It is desirable and in fact preferred that the device thus far described and seen in top view in FIG. 2, be accommodated free standing in the interior of an outer casing 15 which contains the pressure-transmitting fluid, identified with reference numeral 16 and for instance constituted of oil. The level 17.0f the fluid 16 is so selected that the pressure chamber 18 is completely filled with the fluid 16. This can be achieved in various ways, for instanceand as shown in FIG. 1-by selecting the diameter of one or both of the walls 1, 2 so that it is somewhatsmaller than the inner diameter circumscribed by the sections 4, leaving the annular gaps 19. The presence of these gaps does not to any significant extent detract from the effectiveness of the device according to the present invention because the period of time required for development of the interior pressure to the peak value at which venting occurs, is extremely short and during this period the throttling effect which occurs in the gaps 19 is so great that no significant venting of pressure through these gaps can develop in the time in question.

Once deformation of the workpiece 8 has taken place, and venting of the chamber 18 through the gaps 14 has occurred, the unit composed of the elements 1,2,3 and 7 can simply be lifted upwardly out of the confines of the sections 4 which latter remain in the interior of the outer casing 15. During such lifting, the pressure fluid runs out of the space between the elements 1 and 2, and the deformed workpiece can be readily removed to be replaced with a new workpiece, that is a new blank which is to undergo deformation.

The presence of the members 13 provides connection of the sections 4 in such a manner that energy developing in the interior of the chamber 18 during the pressure built up, and which is in excess of the energy required for effecting deformation of the workpiece 8, is not transmitted to the exterior in form of reaction forces, but is, instead, consumed during the relative movement of the sections 4, that is the energy is first stored in the compressed members 13 and subsequently released and used when after venting the members expand and restore the flanges 4a into abutting position.

Coming to the embodiments illustrated in FIGS. 3 and 4, it will be seen that this differs from FIGS. 1 and 2 in that it is the circumferential wall 20 bounding the pressure chamber 18 which is immovable-here consisting of one piece-whereas the top wall 21 and the bottom wall 22 are movable with reference to one another and to the wall 20. For this purpose the walls 21 and 22 are connected with one another by the bolts 22 which are again provided with the spring elements 13 analogous to those shown in FIG. 2. Thus, it is the walls 21 and 22 which perform the relative movements described above with reference to the sections 4 in the embodiments of FIGS. 1 and 2. In addition, the arrangement of the bolts is so selected that with the device in the position shown in FIG. 3, the walls 21 and 22 together with their connecting bolts 23 may be shifted horizontally with reference to the wall 20. This is necessary to permit the introduction into the interior of the pressure chamber 18 of an insert 24 having mounted therein the cartridge 5 and the actuating means 6, as the shock-pressure producing means will be identified hereafter for the sake ofconvenience. In addition, a second insert 25 must be insertable, carrying the die 7. In the illustrated embodiment, the evacuating conduit 11 must of course communicate with the interior space defined between the workpiece 8 and the die 7 via a conduit section provided in the insert 25. To introduce the insert 24, the walls 21,22 and their associate bolts 23 are moved as a unit towards the left-hand side in FIG. 3, and the insert 24 is then inserted from above or from below. Thereupon, the walls 21 and 22 with their bolts 23 are moved as a unit towards the right-hand side from their position illustrated in FIG. 3, the insert 25 is inserted from above or from below, and the walls are then restored to the position shown in FIG. 3.

The device is again accommodated in an outer casing 15, but in this instance, it is secured to the wall of the casing 15 by means of screws 26 which in the illustrated embodiment enter into corresponding bores provided in the circumferential wall 20. Reference numeral 16 again identifies the pressure trans mitting fluid, reference numeral 17 the level of the fluid 16, and reference numeral 14 the gaps corresponding to the gaps 14 of FIGS. 1 and 2 but here defined between the walls 21 and 22, on the one hand, and the inserts 24,25 and circumferential wall 20, on the other hand, through which gaps 14 the interior of the chamber 18 is vented when the peak pressure has been reached. Of course, removal of the inserts 24 and 25 for replacement of the spent cartridge 5 and for removal of the deformed workpiece and replacement with a new blank, is accommodated by a reversal of the shifting motions of the walls 21 and 22.

Coming to the embodiment illustrated in FIGS. 5-7, it will be seen that in principle this corresponds to the preceding embodiments. It is necessary, therefore, to outline herein the differences between this embodiment and the preceding embodiments. Here, the movable walls are again the top wall 21 and the bottom wall 22', and the stationary wall is the circumferential wall 20'. Unlike the embodiment in FIGS. 3 and 4, however, the walls 21' and 22' are not laterally shiftable with reference to the wall 20. Instead, they are each individually secured to the circumferential wall 20' by means of the bolts 26 (compare FIGS. 6 and 7) with the resilient members 13 again being associated with the bolts 26 in the same manner as in the embodiments of FIGS. 1, 2 and 3, 4. The insert 24 carrying the cartridge 5 and the actuating means 6, and the insert 25' carrying the die 7, are here introduced into the chamber 18 by moving them slidably into the chamber laterally of the walls 21 and 22', respectively. Thus, the dimensions of the chamber 18 in the direction of the section line VIVI in FIG. 5, are larger than the corresponding dimensions of the walls 21' and 22, as clearly evident from FIG. 5, of course, as well as from FIG. 6. The excess space is, however, taken up when the inserts 24 and 25' are inserted, in the illustrated embodiment vertically from above by means of the extensions 28 and 29, respectively, which are in turn provided with the handles 32 and 33 (compare FIG. 5).

The outer casing is identified with reference numeral 15' and the device thus far described is again accommodated in the outer casing, being rigidly connected therewith. Reference numeral 16 again identifies the body of pressure-transmitting fluid, and reference numeral 17 the level of the fluid. The casing 15' is closed at its upper side with a cover 27 provided with two cutouts through which the extensions 28 and 29 respectively extend outwardly. To overlay these cutouts, there are provided cover plates 30 and 31, respectively, on the extensions 28 and 29 at the outer side of the cover 27. The iatter will be secured releasably in suitable manner with the circumferential wall of the casing 15.

Under certain circumstances, particularly if the pressuretransmitting fluid 16 is a liquid other than water, for instance oil or if corrosion-inhibiting additives have been included in the water, it may be desirable or even necessary to remove contaminants from the liquid 16. For this purpose the embodiments of FIGS. 5-7 provide a circulating conduit consisting of the sections 34 and 37 of which the former communicates with the interior of the casing 15 near the bottom thereof whereas the latter communicates with the interior of the casing 15 near the top thereof. interposed in this conduit is a circuiating pump 36 effecting circulation of the liquid 16 in the direction indicated by the arrow, and there is further interposed a replaceable filter 35 of suitable construction which is capable of filtering out the undesired impurities. This makes it unnecessary to frequently change the liquid 16 and replace it with new liquid, a factor which would be unnecessarily expensive if the liquid is oil or if the water has corrosion-preven ting additives added to it which of course would have to be replaced with the water and add to the expense of operation.

Coming, finally, to the embodiment illustrated in FIG. 8, it will be seen that it is somewhat similar to the embodiment of FIGS. 5-7. in FlG. 8, however, the shock energy is used for simultaneous deformation of not one but two or even more workpieces 8. To this end, the construction in FIG. 8 which is quite similar to that of FIGS. 5-7, replaces the insert 24 of FIGS. 5-7 with an insert 25" which latter carries an additional die 7 whose surface contour evidently need not be the same as the surface contour of the die 7 carried by the insert 25'. The cartridge 5 and the actuating means 6 therefore are in this embodiment accommodated in the top wall 21" which corresponds to the wall 21' of FIGS. 5-7 but is of course suitably modified to accept the cartridge 5 and the actuating means 6 therefor. In all other respects, the embodiment of FIG. 8 corresponds to that of FIGS. 5-7.

The advantages of the construction according to the present invention will be self-evident. In all embodiments the masses of the dies no longer share the movement of the movable walls, so that the masses of the movable walls can be so related with reference to one another and be coupled elastically in such a manner that the transmission of reaction forces to the exterior of the device is avoided. Furthermore, the elastic coupling of the movable walls, in accordance with the present invention, limits the extent to which the movable walls can move, and therefore makes it possible to decrease the overall size of the device.

In no case are connections (i.e., the evacuating conduits) with the dies or with the cartridge 5 of such type that they have to be movable, that is no such connections are associated with components of the device which are movable in response to development of interior pressure. Because these connections are now stationary with reference to the frame or support of the device, mechanization and automation of the operation of devices of this type is greatly facilitated.

A further advantage results from the limiting of the movement which can be performed by the movable components, in conjunction with the fact that connection with the dies and with the cartridge are stationary. The result of this is the fact that the device can be operated in a relatively small-dimensioned closed outer casing containing the pressure-transmitting fluid. This eliminates the provision of separate filling devices filling the interior of the pressure chamber with pressure fluid and not only avoids the expense for providing such devices, but also reduces the time heretofore required for the operation of these devices.

Because the device, according to the present invention, can be operated in a closed outer casing, the noise produced during its operation is considerably less than heretofore the case, particularly with respect to the high frequency which had been especially objectionable, and the safety of operation is significantly increased.

Finally, the use of more than one die simultaneously, especially in the embodiments of FIGS. 3-8, increases the economy of operation ofthe device.

It will be appreciated that it is for instance possible to effect movement of the inserts 24,25, etc. by means of suitable pulleys and counterweights, which is particularly desirable if the devices are of relatively large construction because the weights involved are of course significant. The simple kinematic of movement of the insertswhether they carry the cartridge and actuating means or the die or dies-makes possible the use of hydraulic, pneumatic, or mechanical devices for effecting such movement, and moreover of devices which are readily available commercially. This, of course, makes the device according to the present invention particularly economical because it can be readily used with auxiliary devices which are available without difficulty through commercial channels, and it can be used with devices which permit either manual or automated operation.

Finally, it should be mentioned that ifa device according to the present invention is operated in an outer casing which is closed and contains the pressure-transmitting fluid, then it is advantageous not to completely fill the outer casing so that the remaining air-filled space acts as a buffer and prevents the transmission of shock to the wall of the outer casing.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a device for shock-deformation of workpieces, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims 1. A device for shock-deformation of workpieces, comprising rigid wall means surrounding a pressure chamber arranged to accommodate a workpiece and a die having a surface contour which is to be imparted to said workpiece by shock-deformation of the latter into conformance with said surface contour, said wall means including a top end wall, a bottom end wall, and a peripheral wall comprising at least two wall sections at least one of which is movable relative to the other between a chamber-closing position and a chamber-opening position, said wall sections having an inertia so selected as to at least substantially equal the necessary shock-pressure for producing the predetermined energy level requisite to obtain the desired deformation of said workpiece so that upon exceeding of said necessary shock-pressure relative movement of said wall sections to said chamber-opening position results with concomitant venting of said chamber; securing means rigidly securing said top end wall and said bottom end wall to one another against relative movement; shock-pressure producing means for producing a sudden increase in pressure in said chamber; and energy-consuming elastically yieldable connecting means connecting said wall sections to one another and being operative for elastically yielding and thereby consuming shock-pressure energy in excess of said predetermined level during movement of said wall sections.

2. A device as defined in claim 1 wherein said wall sections are arranged for traversing a substantially vertical path during movement from one to the other of said positions.

3. A device as defined in claim 1, wherein saidwall sections are arranged for traversing a substantially horizontal path during movement from one to the other of said positions.

4. A device as defined in claim 1; and further comprising a die having said surface contour and being accommodated in the interior of said pressure chamber.

5. A device as defined in claim 4, wherein said die is removably accommodated in the interior of said pressure chamber.

6. A device as defined in claim 4; and further comprising at least one additional die also accommodated in the interior of said pressure chamber and also having a predetermined surface contour which is to be imparted to an additional workpiece.

7. A device as defined in claim 1; wherein said die is rigid with said bottom wall.

8. A device as defined in claim 4; further comprising an insert member insertable into and withdrawable from said pressure chamber, and wherein said die is mounted on said insert member.

9. A device as defined in claim 1; further comprising an insert element insertable into and withdrawable from said pressure chamber, and wherein said shock-pressure producing means is carried by said insert element.

10. A device as defined in claim 1; and further comprising an outer casing surrounding said wall means; and a body of pressure-transmitting fluid accommodated in said outer casing and in said pressure chamber.

11. A device as defined in claim 10, said fluid being a liquid; and further comprising cleaning means for removing contaminants from said liquid.

12. A device as defined in claim 11, said cleaning means comprising conduit means having an inlet and an outlet both communicating with the interior of said outer casing, circulating means for circulating said liquid through said conduit means, and contaminant-removing means for removing contaminants from said liquid circulating through said conduit means.

13. A device as defined in claim 1, wherein said shock-pressure producing means is rigid with one of said end walls.

14. A device as defined in claim 10, said outer casing being a closed casing. 

1. A device for shock-deformation of workpieces, comprising rigid wall means surrounding a pressure chamber arranged to accommodate a workpiece and a die having a surface contour which is to be imparted to said workpiece by shock-deformation of the latter into conformance with said surface contour, said wall means including a top end wall, a bottom end wall, and a peripheral wall comprising at least two wall sections at least one of which is movable relative to the other between a chamberclosing position and a chamber-opening position, said wall sections having an inertia so selected as to at least substantially equal the necessary shock-pressure for producing the predetermined energy level requisite to obtain the desired deformation of said workpiece so that upon exceeding of said necessary shock-pressure relative movement of said wall sections to said chamber-opening position results with concomitant venting of said chamber; securing means rigidly securing said top end wall and said bottom end wall to one another against relative movement; shock-pressure producing means for producing a sudden increase in pressure in said chamber; and energy-consuming elastically yieldable connecting means connecting said wall sections to one another and being operative for elastically yielding and thereby consuming shock-pressure energy in excess of said predetermined level during movement of said wall sections.
 2. A device as defined in claim 1, wherein said wall sections are arranged for traversing a substantially vertical path during movement from one to the other of said positions.
 3. A device as defined in claim 1, wherein said wall sections are arranged for traversing a substantially horizontal path during movement from one to the other of said positions.
 4. A device as defined in claim 1; and further comprising a die having said surface contour and being accommodated in the interior of said pressure chamber.
 5. A device as defined in claim 4, wherein said die is removably accommodated in the interior of said pressure chamber.
 6. A device as defined in claim 4; and further comprising at least one additional die also accommodated in the interior of said pressure chamber and also having a predetermined surface contour which is to be imparted to an additional workpiece.
 7. A device as defined in claim 1; wherein said die is rigid with said bottom wall.
 8. A device as defined in claim 4; further comprising an insert member insertable into and withdrawable from said pressure chamber, and wherein said die is mounted on said insert member.
 9. A device as defined in claim 1; further comprising an insert element insertable into and withdrawable from said pressure chamber, and wherein said shock-pressure producing means is carried by said insert element.
 10. A device as defined in claim 1; and further comprising an outer casing surrounding said wall means; and a body of pressure-transmitting fluid accommodated in said outer casing and in said pressure chamber.
 11. A device as defined in claim 10, said fluid being a liquid; and further comprising cleaning means for removing contaminants from said liquid.
 12. A device as defined in claim 11, said cleaning means comprising conduit means having an inlet and an outlet both communicating with the interior of said outer casing, circulating means for circulating said liquid through said conduit means, and contaminant-removing means for removing contaminants from said liquid circulating through said conduit means.
 13. A device as defined in claim 1, wherein said shock-pressure producing means is rigid with one of said end walls.
 14. A device as defined in claim 10, said outer casing being a closed casing. 